The field of the invention pertains to automotive fuel tanks, and in particular, to the fill pipes of such tanks. Typically, the fill pipe extends upwardly into a chamber or cavity covered by a spring urged access door. The upper end of the fill pipe is closed by a cap. The door is opened, the cap removed and a tubular nozzle inserted into the fill pipe to add fuel to the tank. The fit of the nozzle into the fill pipe is generally very loose and most fuels, in particular gasoline, are relatively non-viscous. As a result splash back of fuel up the fill pipe and out the opening is not an infrequent event. Such splash back dirties clothing, is disagreeably odorous and contains known carcinogens. There is also a potential fire hazard.
As a result a number of devices have been developed to control splash back. U.S. Pat. No. 1,903,139 discloses a metal baffle attached to the outside of the nozzle. More recently U.S. Pat. No. 3,451,445 discloses a frusto-conical spongy baffle to catch and retain liquid fuel but permit air to pass therethrough and U.S. Pat. No. 3,739,988 discloses a plastic baffle attached to the outside of the nozzle.
U.S. Pat. No. 3,903,942 discloses a flexible duckbill valve that grasps the nozzle upon insertion in the fill pipe. Although directed to prevention of vapor emissions from the fill pipe, the valve also is directed to prevention of liquid splash. U.S. Pat. No. 4,326,641 discloses an anti-siphon tube depending from a baffle within the upper end of the fill pipe. The baffle also acts as a splash back preventer although some splash back can occur about a loose fitting nozzle.
Most motor vehicles are not equipped with anti-splash back devices as disclosed in the prior art and filling stations do not all make a practice of fitting nozzles with suitable baffles. Thus, a need exists for an after market splash guard that can be easily installed by the novice owner or operator of a motor vehicle.